Bug Summary

File:lib/nettle/egd.c
Location:line 206, column 3
Description:Value stored to 'do_restart' is never read

Annotated Source Code

1/* rndegd.c - interface to the EGD
2 * Copyright (C) 1999-2000, 2002-2003, 2010, 2012 Free Software
3 * Foundation, Inc.
4 *
5 * This file is part of Libgcrypt.
6 *
7 * Libgcrypt is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 3 of
10 * the License, or (at your option) any later version.
11 *
12 * Libgcrypt is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>
19 *
20 */
21
22#include <config.h>
23
24#ifndef _WIN32
25
26#include <stdio.h>
27#include <stdlib.h>
28#include <errno(*__errno_location ()).h>
29#include <sys/time.h>
30#include <sys/stat.h>
31#include <string.h>
32#include <unistd.h>
33#include <sys/types.h>
34#include <sys/socket.h>
35#include <sys/un.h>
36#include "egd.h"
37#include <gnutls_int.h>
38#include <gnutls_str.h>
39#include <gnutls_errors.h>
40
41#ifdef AF_UNIX1
42# define LOCAL_SOCKET_TYPE1 AF_UNIX1
43#else
44# define LOCAL_SOCKET_TYPE1 AF_LOCAL1
45#endif
46
47#ifndef offsetof
48#define offsetof(type, member)__builtin_offsetof(type, member) ((size_t) &((type *)0)->member)
49#endif
50
51static int egd_socket = -1;
52
53static int
54do_write (int fd, void *buf, size_t nbytes)
55{
56 size_t nleft = nbytes;
57 int nwritten;
58
59 while (nleft > 0)
60 {
61 nwritten = write (fd, buf, nleft);
62 if (nwritten < 0)
63 {
64 if (errno(*__errno_location ()) == EINTR4)
65 continue;
66 return -1;
67 }
68 nleft -= nwritten;
69 buf = (char *) buf + nwritten;
70 }
71 return 0;
72}
73
74static int
75do_read (int fd, void *buf, size_t nbytes)
76{
77 int n, nread = 0;
78
79 do
80 {
81 do
82 {
83 n = read (fd, (char *) buf + nread, nbytes);
84 }
85 while (n == -1 && errno(*__errno_location ()) == EINTR4);
86 if (n == -1)
87 return nread ? nread : -1;
88 if (n == 0)
89 return -1;
90 nread += n;
91 nbytes -= n;
92 }
93 while (nread < nbytes);
94 return nread;
95}
96
97static const char *egd_names[] = {
98 "/var/run/egd-pool",
99 "/dev/egd-pool",
100 "/etc/egd-pool",
101 "/etc/entropy",
102 "/var/run/entropy",
103 "/dev/entropy",
104 NULL((void*)0)
105};
106
107static const char *
108find_egd_name (void)
109{
110 int i = 0;
111 struct stat st;
112
113 do
114 {
115 if (stat (egd_names[i], &st) != 0)
116 continue;
117
118 if (st.st_mode & S_IFSOCK0140000)
119 { /* found */
120 return egd_names[i];
121 }
122
123 }
124 while (egd_names[++i] != NULL((void*)0));
125
126 return NULL((void*)0);
127}
128
129/* Connect to the EGD and return the file descriptor. Return -1 on
130 error. With NOFAIL set to true, silently fail and return the
131 error, otherwise print an error message and die. */
132int
133_rndegd_connect_socket (void)
134{
135 int fd;
136 const char *name;
137 struct sockaddr_un addr;
138 int addr_len;
139
140 if (egd_socket != -1)
141 {
142 close (egd_socket);
143 egd_socket = -1;
144 }
145
146 name = find_egd_name ();
147
148 if (strlen (name) + 1 >= sizeof addr.sun_path)
149 {
150 _gnutls_debug_log ("EGD socketname is too long\n")do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "EGD socketname is too long\n"); } while(0);
151 return -1;
152 }
153
154 memset (&addr, 0, sizeof addr);
155 addr.sun_family = LOCAL_SOCKET_TYPE1;
156 _gnutls_str_cpy (addr.sun_path, sizeof(addr.sun_path), name);
157 addr_len = (offsetof (struct sockaddr_un, sun_path)__builtin_offsetof(struct sockaddr_un, sun_path)
158 + strlen (addr.sun_path));
159
160 fd = socket (LOCAL_SOCKET_TYPE1, SOCK_STREAMSOCK_STREAM, 0);
161 if (fd == -1)
162 {
163 _gnutls_debug_log ("can't create unix domain socket: %s\n",do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "can't create unix domain socket: %s\n", rpl_strerror ((
*__errno_location ()))); } while(0)
164 strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "can't create unix domain socket: %s\n", rpl_strerror ((
*__errno_location ()))); } while(0);
165 return -1;
166 }
167 else if (connect (fd, (struct sockaddr *) &addr, addr_len) == -1)
168 {
169 _gnutls_debug_log ("can't connect to EGD socket `%s': %s\n",do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "can't connect to EGD socket `%s': %s\n", name, rpl_strerror
((*__errno_location ()))); } while(0)
170 name, strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "can't connect to EGD socket `%s': %s\n", name, rpl_strerror
((*__errno_location ()))); } while(0);
171 close (fd);
172 fd = -1;
173 }
174
175 if (fd != -1)
176 egd_socket = fd;
177 return fd;
178}
179
180/****************
181 * Note: We always use the highest level.
182 * To boost the performance we may want to add some
183 * additional code for level 1
184 *
185 * Using a level of 0 should never block and better add nothing
186 * to the pool. So this is just a dummy for EGD.
187 */
188int
189_rndegd_read (int *fd, void *_output, size_t _length)
190{
191 int n;
192 uint8_t buffer[256 + 2];
193 int nbytes;
194 int do_restart = 0;
195 unsigned char *output = _output;
196 size_t length = _length;
197
198 if (!length)
199 return 0;
200
201
202restart:
203 if (*fd == -1 || do_restart)
204 *fd = _rndegd_connect_socket ();
205
206 do_restart = 0;
Value stored to 'do_restart' is never read
207
208 nbytes = length < 255 ? length : 255;
209 /* First time we do it with a non blocking request */
210 buffer[0] = 1; /* non blocking */
211 buffer[1] = nbytes;
212
213 if (do_write (*fd, buffer, 2) == -1)
214 _gnutls_debug_log ("can't write to the EGD: %s\n", strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "can't write to the EGD: %s\n", rpl_strerror ((*__errno_location
()))); } while(0);
215
216 n = do_read (*fd, buffer, 1);
217 if (n == -1)
218 {
219 _gnutls_debug_log ("read error on EGD: %s\n", strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "read error on EGD: %s\n", rpl_strerror ((*__errno_location
()))); } while(0);
220 do_restart = 1;
221 goto restart;
222 }
223
224 n = buffer[0];
225 if (n)
226 {
227 n = do_read (*fd, buffer, n);
228 if (n == -1)
229 {
230 _gnutls_debug_log ("read error on EGD: %s\n", strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "read error on EGD: %s\n", rpl_strerror ((*__errno_location
()))); } while(0);
231 do_restart = 1;
232 goto restart;
233 }
234
235 if (n > length)
236 {
237 _gnutls_debug_log ("read error on EGD: returned more bytes!\n")do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "read error on EGD: returned more bytes!\n"); } while(0);
238 n = length;
239 }
240
241 memcpy (output, buffer, n);
242 output += n;
243 length -= n;
244 }
245
246 while (length)
247 {
248 nbytes = length < 255 ? length : 255;
249
250 buffer[0] = 2; /* blocking */
251 buffer[1] = nbytes;
252 if (do_write (*fd, buffer, 2) == -1)
253 _gnutls_debug_log ("can't write to the EGD: %s\n", strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "can't write to the EGD: %s\n", rpl_strerror ((*__errno_location
()))); } while(0);
254 n = do_read (*fd, buffer, nbytes);
255 if (n == -1)
256 {
257 _gnutls_debug_log ("read error on EGD: %s\n", strerror (errno))do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "read error on EGD: %s\n", rpl_strerror ((*__errno_location
()))); } while(0);
258 do_restart = 1;
259 goto restart;
260 }
261
262 if (n > length)
263 {
264 _gnutls_debug_log ("read error on EGD: returned more bytes!\n")do { if (__builtin_expect((_gnutls_log_level >= 2), 0)) _gnutls_log
( 2, "read error on EGD: returned more bytes!\n"); } while(0);
265 n = length;
266 }
267
268 memcpy (output, buffer, n);
269 output += n;
270 length -= n;
271 }
272
273 return _length; /* success */
274}
275
276#endif